Institute of Chemical Technologies and Analytics

Vienna, Austria

Institute of Chemical Technologies and Analytics

Vienna, Austria

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Mohsin I.U.,Institute of Chemical Technologies and Analytics | Lager D.,AIT Austrian Institute of Technology | Gierl C.,Institute of Chemical Technologies and Analytics | Hohenauer W.,AIT Austrian Institute of Technology | Danninger H.,Institute of Chemical Technologies and Analytics
Thermochimica Acta | Year: 2010

The thermal de-binding of a metal injection molded (MIM) copper part was investigated at four different heating rates using a thermo-nanobalance coupled with infrared (FTIR) and mass spectrometry (MS), respectively. The FTIR and MS analysis have been employed to study the chemical reactions during thermal decomposition of the MIM polymeric binder. These techniques are effective for determining the thermal stability and product evolution as a function of temperature. The polymeric binder decomposition starts at approximately 250 °C yielding hydrocarbons in the C1-C6 range, with methane, ethylene, propylene, C4 and C5 composing the majority of gaseous products. The major decomposition reaction of polymeric binder was found to be autocatalytic. By using Netzsch thermo-kinetics software, a non-linear regression model was established. The predicted chemical reactions for the MIM thermal de-binding model were found to agree well with the calculated model curves. © 2010 Elsevier B.V. All rights reserved.


Zlatkov B.S.,Fotec GmbH | Mitrovic N.S.,University of Kragujevac | Nikolic M.V.,Serbian Institute for Multidisciplinary Research | Maricic A.M.,University of Kragujevac | And 3 more authors.
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2010

In this work, manganese zinc ferrite components were manufactured by powder injection molding - PIM technology. A fine powder consisting of Mn 1-xZnxFe2O4 with small addition of hematite α-Fe2O3 as used in mass ferrite production was mixed with an organic binder (Solvent System) to form ferrite feedstock for powder injection molding - PIM technology. Excess of Fe2O3 was present in the starting powder in order to suppress conversion of Fe 3+ to Fe2+ ions which would lower the permeability. The ferrite feedstock was injected in a mold with a cavity shaped like a small cylinder with a hole on the main axis. Injection molded samples were then solvent and thermally debinded and sintered in different atmospheres: air, argon and nitrogen. The starting powder, injected green samples and sintered samples were characterized using X-ray diffractometry, scanning electron microscopy, thermogravimetry, differential thermal analysis as well as by magnetic measurements. Rietveld refinement of measured X-ray patterns was done to detect possible phase transformations of Fe2O3 to other iron oxides through reduction by binder residues (carbon) at elevated temperatures during thermal debinding and sintering. Finally, the magnetic properties were measured by hysteresis graph and mutually compared for the injected samples that were sintered in air, argon and nitrogen. The obtained magnetic characteristics where found to be comparable with commercial samples prepared by traditional sintering technology. © 2010 Elsevier B.V.


Kubel F.,Institute of Chemical Technologies and Analytics | Pantazi M.,Institute of Chemical Technologies and Analytics | Hagemann H.,University of Geneva
Zeitschrift fur Anorganische und Allgemeine Chemie | Year: 2014

The compound Ba5I2O12 was synthesized by heating a precipitate of dissolved Ba(OH)28H2O and H5IO6. Rb2 O was added to increase the crystallite size. The crystal structure was determined from conventional laboratory X-ray diffraction data by using a real-space structure solution approach followed by a Rietveld refinement. No constraints on positions were used. The structure analysis gave an ortho-rhombic symmetry with a = 19.7474(2) Å, b = 5.9006(1) Å and c = 10.5773(1) Å. The final RBragg value in space group Pnma (62) was 1.0%. The structure can be described by layers of a metal and iodine arrangement forming almost pentagonal holes. Raman measurements were correlated with the two IO6 octahedra. Two further barium periodate patterns were observed and indexed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Uzunova E.L.,Bulgarian Academy of Science | Mikosch H.,Institute of Chemical Technologies and Analytics | St. Nikolov G.,Bulgarian Academy of Science
International Journal of Quantum Chemistry | Year: 2013

DFT periodic, ONIOM, and cluster studies with all-electron basis sets are applied to Cu(I) exchanged zeolites and silicoalumino-phosphate analogs with faujasite and chabazite topology. The reactivity of the cations at different cation positions is probed by NO adsorption. In the ONIOM approach, the cation center and the nearest framework environment are described by DFT, whereas a larger part of the structure is modeled at the semiempirical PM6 level. The importance of including all electrons explicitly in the periodic model computations is outlined by comparison of the results with those from ONIOM and previous plane-wave studies. The Cu(I) cations reside at distinct extraframework cation sites in the vicinity of the double six-membered rings (D6R) and upon adsorption they experience a displacement from their previous position. A full optimization with all-electron basis set is a prerequisite for proper elucidation of the coordination of the transition metal cations by the framework oxygen atoms. © 2012 Wiley Periodicals, Inc.


de Oro Calderon R.,Institute of Chemical Technologies and Analytics | Gierl-Mayer C.,Institute of Chemical Technologies and Analytics | Danninger H.,Institute of Chemical Technologies and Analytics
Journal of Thermal Analysis and Calorimetry | Year: 2016

For the consolidation of steel parts manufactured by powder metallurgy (PM) techniques, removal of the surface oxides covering metallic powder particles is a necessary prerequisite. In PM steels with conventional compositions, reduction of the oxides is easily achieved in traditional sintering furnaces. However, processing steels containing alloying elements with a high oxygen affinity represents a big challenge that requires a deeper understanding of the chemical processes occurring during sintering. In the present work, thermogravimetry analysis coupled with mass spectrometry is used to describe the oxidation/reduction phenomena that take place when sintering steel powders and how these processes are modified by the addition of admixed particles containing oxygen-sensitive elements. Carbothermal reduction processes are studied using pure oxides (Fe2O3, MnO2, Cr2O3 and SiO2) as well as water-atomized Fe powders mixed with small amounts—4 mass/%—of Cr, Mn and Si powders or Fe–Mn–Si–(Cr) master alloy powders. The results show that there is an oxygen transfer from the base iron particles to the oxidation-sensitive elements—“internal getter effect”—taking place mostly through the gas phase. Different alloying elements (Cr, Mn, Si) show different temperature ranges of susceptibility to oxidation. Combination of these oxygen-sensitive alloying elements in the form of a master alloy powder reduces their sensitivity to oxidation. Also, the use of master alloys promotes the concentration of the oxides on the surface of the alloying particles and not in the grain boundaries of the surrounding iron particles—as occurs when using Mn carriers—which should have a beneficial impact on the final mechanical performance. © 2016 The Author(s)


PubMed | Institute of Applied Synthetic Chemistry and Institute of Chemical Technologies and Analytics
Type: Journal Article | Journal: Acta crystallographica Section B, Structural science, crystal engineering and materials | Year: 2015

The systematic twinning of three 2,6-diaminopyridine-based Fe-PNP complexes is interpreted using order-disorder (OD) theory. The monoclinic [Fe(0)(PNP(Et)-(i)Pr)(CO)2] [P112(1)/b, Z = 4] possesses pseudo-orthorhombic metrics and crystallizes as a reflection twin by pseudo-merohedry with the twin plane (100). The structure is made up of layers with idealized p2(1)a(b) symmetry. The a glide planes of adjacent layers do not overlap, leading to OD polytypism. trans-[Fe(II)(PNP-Et)Br2(CO)] [P2(1)/n, Z = 1] is systematically twinned via twofold rotation about [001]. It is made up of OD layers with idealized p2(1)2(1)(2) symmetry. OD polytypism is caused by the twofold rotation axes of adjacent layers which do not overlap. [Fe(II)((2)P,N-PNP-(i)Pr,TAD)Cl2]THF [P1, Z^{\prime} = 2] is systematically twinned via a twofold rotation about [010]. It is made up of layers with idealized p121(1) symmetry. OD polytypism is caused by screw rotations relating adjacent layers with an intrinsic translation along a fourth of a primitive lattice vector. In all three structures the twin individuals are a polytype with a maximum degree of order (MDO) and at the twin interface is located a fragment of the second MDO polytype.


Home > Press > The quantum sniffer dog: A laser and detector in 1: A microscopic sensor has been developed at TU Wien, which can be used to identify different gases simultaneously Abstract: As humans, we sniff out different scents and aromas using chemical receptors in our noses. In technological gas detection, however, there are a whole host of other methods available. One such method is to use infrared lasers, passing a laser beam through the gas to an adjacent separate detector, which measures the degree of light attenuation it causes. TU Wien's tiny new sensor now brings together both sides within a single component, making it possible to use the same microscopic structure for both the emission and detection of infrared radiation. Circular quantum cascade lasers "The lasers that we produce are a far cry from ordinary laser pointers ," explains Rolf Szedlak from the Institute of Solid State Electronics at TU Wien. "We make what are known as quantum cascade lasers. They are made up of a sophisticated layered system of different materials and emit light in the infrared range." When an electrical voltage is applied to this layered system, electrons pass through the laser. With the right selection of materials and layer thicknesses, the electrons always lose some of their energy when passing from one layer into the next. This energy is released in the form of light, creating an infrared laser beam. "Our quantum cascade lasers are circular, with a diameter of less than half a millimetre," reports Prof. Gottfried Strasser, head of the Center for Micro- and Nanostructures at TU Wien. "Their geometric properties help to ensure that the laser only emits light at a very specific wavelength." "This is perfect for chemical analysis of gases, as many gases absorb only very specific amounts of infrared light," explains Prof. Bernhard Lendl from the Institute of Chemical Technologies and Analytics at TU Wien. Gases can thus be reliably detected using their own individual infrared 'fingerprint'. Doing so requires a laser with the correct wavelength and a detector that measures the amount of infrared radiation swallowed up by the gas. A laser that also detects "Our microscopic structure has the major advantage of being a laser and detector in one," professes Rolf Szedlak. Two concentric quantum cascade rings are fitted for this purpose, which can both (depending on the operating mode) emit and detect light, even doing so at two slightly different wavelengths. One ring emits the laser light which passes through the gas before being reflected back by a mirror. The second ring then receives the reflected light and measures its strength. The two rings then immediately switch their roles, allowing the next measurement to be carried out. In testing this new form of sensor, the TU Wien research team faced a truly daunting challenge: they had to differentiate isobutene and isobutane - two molecules which, in addition to confusingly similar names, also possess very similar chemical properties. The microscopic sensors passed this test with flying colours, reliably identifying both of the gases. "Combining laser and detector brings many advantages," says Gottfried Strasser. "It allows for the production of extremely compact sensors, and conceivably, even an entire array - i.e. a cluster of microsensors - housed on a single chip and able to operate on several different wavelengths simultaneously." The application possibilities are virtually endless, ranging from environmental technology to medicine. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


News Article | October 25, 2016
Site: www.cemag.us

As humans, we sniff out different scents and aromas using chemical receptors in our noses. In technological gas detection, however, there are a whole host of other methods available. One such method is to use infrared lasers, passing a laser beam through the gas to an adjacent separate detector, which measures the degree of light attenuation it causes. TU Wien’s tiny new sensor now brings together both sides within a single component, making it possible to use the same microscopic structure for both the emission and detection of infrared radiation. “The lasers that we produce are a far cry from ordinary laser pointers,” explains Rolf Szedlak from the Institute of Solid State Electronics at TU Wien. “We make what are known as quantum cascade lasers. They are made up of a sophisticated layered system of different materials and emit light in the infrared range.” When an electrical voltage is applied to this layered system, electrons pass through the laser. With the right selection of materials and layer thicknesses, the electrons always lose some of their energy when passing from one layer into the next. This energy is released in the form of light, creating an infrared laser beam. “Our quantum cascade lasers are circular, with a diameter of less than half a millimeter,” reports Professor Gottfried Strasser, head of the Center for Micro- and Nanostructures at TU Wien. “Their geometric properties help to ensure that the laser only emits light at a very specific wavelength.” “This is perfect for chemical analysis of gases, as many gases absorb only very specific amounts of infrared light,” explains Prof. Bernhard Lendl from the Institute of Chemical Technologies and Analytics at TU Wien. Gases can thus be reliably detected using their own individual infrared ‘fingerprint’. Doing so requires a laser with the correct wavelength and a detector that measures the amount of infrared radiation swallowed up by the gas. “Our microscopic structure has the major advantage of being a laser and detector in one,” says Szedlak. Two concentric quantum cascade rings are fitted for this purpose, which can both (depending on the operating mode) emit and detect light, even doing so at two slightly different wavelengths. One ring emits the laser light which passes through the gas before being reflected back by a mirror. The second ring then receives the reflected light and measures its strength. The two rings then immediately switch their roles, allowing the next measurement to be carried out. In testing this new form of sensor, the TU Wien research team faced a truly daunting challenge: they had to differentiate isobutene and isobutane — two molecules which, in addition to confusingly similar names, also possess very similar chemical properties. The microscopic sensors passed this test with flying colors, reliably identifying both of the gases. “Combining laser and detector brings many advantages,” says Strasser. “It allows for the production of extremely compact sensors, and conceivably, even an entire array — i.e. a cluster of microsensors — housed on a single chip and able to operate on several different wavelengths simultaneously.” The application possibilities are virtually endless, ranging from environmental technology to medicine.


News Article | October 26, 2016
Site: www.eurekalert.org

A laser and detector in 1: A microscopic sensor has been developed at TU Wien, which can be used to identify different gases simultaneously As humans, we sniff out different scents and aromas using chemical receptors in our noses. In technological gas detection, however, there are a whole host of other methods available. One such method is to use infrared lasers, passing a laser beam through the gas to an adjacent separate detector, which measures the degree of light attenuation it causes. TU Wien's tiny new sensor now brings together both sides within a single component, making it possible to use the same microscopic structure for both the emission and detection of infrared radiation. "The lasers that we produce are a far cry from ordinary laser pointers ," explains Rolf Szedlak from the Institute of Solid State Electronics at TU Wien. "We make what are known as quantum cascade lasers. They are made up of a sophisticated layered system of different materials and emit light in the infrared range." When an electrical voltage is applied to this layered system, electrons pass through the laser. With the right selection of materials and layer thicknesses, the electrons always lose some of their energy when passing from one layer into the next. This energy is released in the form of light, creating an infrared laser beam. "Our quantum cascade lasers are circular, with a diameter of less than half a millimetre," reports Prof. Gottfried Strasser, head of the Center for Micro- and Nanostructures at TU Wien. "Their geometric properties help to ensure that the laser only emits light at a very specific wavelength." "This is perfect for chemical analysis of gases, as many gases absorb only very specific amounts of infrared light," explains Prof. Bernhard Lendl from the Institute of Chemical Technologies and Analytics at TU Wien. Gases can thus be reliably detected using their own individual infrared 'fingerprint'. Doing so requires a laser with the correct wavelength and a detector that measures the amount of infrared radiation swallowed up by the gas. "Our microscopic structure has the major advantage of being a laser and detector in one," professes Rolf Szedlak. Two concentric quantum cascade rings are fitted for this purpose, which can both (depending on the operating mode) emit and detect light, even doing so at two slightly different wavelengths. One ring emits the laser light which passes through the gas before being reflected back by a mirror. The second ring then receives the reflected light and measures its strength. The two rings then immediately switch their roles, allowing the next measurement to be carried out. In testing this new form of sensor, the TU Wien research team faced a truly daunting challenge: they had to differentiate isobutene and isobutane - two molecules which, in addition to confusingly similar names, also possess very similar chemical properties. The microscopic sensors passed this test with flying colours, reliably identifying both of the gases. "Combining laser and detector brings many advantages," says Gottfried Strasser. "It allows for the production of extremely compact sensors, and conceivably, even an entire array - i.e. a cluster of microsensors - housed on a single chip and able to operate on several different wavelengths simultaneously." The application possibilities are virtually endless, ranging from environmental technology to medicine.


News Article | October 25, 2016
Site: www.rdmag.com

As humans, we sniff out different scents and aromas using chemical receptors in our noses. In technological gas detection, however, there are a whole host of other methods available. One such method is to use infrared lasers, passing a laser beam through the gas to an adjacent separate detector, which measures the degree of light attenuation it causes. TU Wien's tiny new sensor now brings together both sides within a single component, making it possible to use the same microscopic structure for both the emission and detection of infrared radiation. "The lasers that we produce are a far cry from ordinary laser pointers ," explains Rolf Szedlak from the Institute of Solid State Electronics at TU Wien. "We make what are known as quantum cascade lasers. They are made up of a sophisticated layered system of different materials and emit light in the infrared range." When an electrical voltage is applied to this layered system, electrons pass through the laser. With the right selection of materials and layer thicknesses, the electrons always lose some of their energy when passing from one layer into the next. This energy is released in the form of light, creating an infrared laser beam. "Our quantum cascade lasers are circular, with a diameter of less than half a millimetre," reports Prof. Gottfried Strasser, head of the Center for Micro- and Nanostructures at TU Wien. "Their geometric properties help to ensure that the laser only emits light at a very specific wavelength." "This is perfect for chemical analysis of gases, as many gases absorb only very specific amounts of infrared light," explains Prof. Bernhard Lendl from the Institute of Chemical Technologies and Analytics at TU Wien. Gases can thus be reliably detected using their own individual infrared 'fingerprint'. Doing so requires a laser with the correct wavelength and a detector that measures the amount of infrared radiation swallowed up by the gas. "Our microscopic structure has the major advantage of being a laser and detector in one," professes Rolf Szedlak. Two concentric quantum cascade rings are fitted for this purpose, which can both (depending on the operating mode) emit and detect light, even doing so at two slightly different wavelengths. One ring emits the laser light which passes through the gas before being reflected back by a mirror. The second ring then receives the reflected light and measures its strength. The two rings then immediately switch their roles, allowing the next measurement to be carried out. In testing this new form of sensor, the TU Wien research team faced a truly daunting challenge: they had to differentiate isobutene and isobutane - two molecules which, in addition to confusingly similar names, also possess very similar chemical properties. The microscopic sensors passed this test with flying colours, reliably identifying both of the gases. "Combining laser and detector brings many advantages," says Gottfried Strasser. "It allows for the production of extremely compact sensors, and conceivably, even an entire array - i.e. a cluster of microsensors - housed on a single chip and able to operate on several different wavelengths simultaneously." The application possibilities are virtually endless, ranging from environmental technology to medicine.

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